There are known knowns; there are things we know we know; we also know there are unknowns; that is to say, we know there are things that we do not know. But there are also unknown unknowns—the ones we don’t know we don’t know.
—Donald Rumsfeld, commenting on the run-up to the 2003 invasion of Iraq.
Within a couple of months after I was diagnosed with Alzheimer’s in June 2015, I had a revelation. My understanding, at that time, was at a rudimentary stage. Previously, I’d assumed that the only way I could have developed the disease was to inherit it from someone within my family tree. After examining both sides of my extended family, my Anglo side and my Croatian side, I could find no obvious culprit. Two of my four grandparents lived into their sixties, with no signs of dementia. Another died young, in a logging accident, but his parents each lived well into their nineties. My paternal grandmother, who grew up on an island in the Adriatic Sea, died in middle age, from complications of a childhood illness in an era before the advent of antibiotics. But given the link between diet and Alzheimer’s, it’s unlikely that my paternal grandmother would have been carrying the APOE4 gene, which heightens the risk of developing Alzheimer’s. The disease appears to be less common in the Mediterranean region than in northern Europe or North America.
Then I had an epiphany. I recalled that I’d been knocked out for about fifteen minutes when I fell off my brother’s back bicycle fender at the age of six or seven, in an era when almost no cyclists wore helmets. But, recently, I was disabused of the notion that my single concussion could have accounted for my Alzheimer’s diagnosis. Any concussion would have to had lasted at least 30 minutes to sustain the kind of brain damage that could lead to Alzheimer’s directly, many decades later. And, recently, my mom confirmed that I was unconscious for only about fifteen minutes. What that concussion probably did do to me was to leave me with a permanent poor sense of direction, but no more dire consequences.
A more plausible thesis, though, is that “subconcussions,” a relatively new understood phenomenon among head trauma, could have accounted for my dementia. In the 1970s, when I was playing football, coaches often sanctioned “live” hitting during practices almost every day of practice. And I might have been particularly vulnerable because of my small stature (five-foot-seven, 135 pounds, as a high school sophomore). By the time I was a senior I had largely matured physically, but perhaps the damage had already been done.
Recently, I reached out to Shannon Conneely of the Boston University’s BU CTE Center, to see if my appropriate diagnosis could be CTE—short for chronic traumatic encephalopathy. First, Conneelly noted, CTE’s symptoms tend to appear in one’s late forties, and early-onset Alzheimer’s (my diagnosis) typically begins in one’s fifties or later. The most stark difference between the two diagnoses is that people with CTE are much more likely to have weak impulse control and poor judgment, which can lead to aggression, and, in some cases, suicide.
If I had to speculate on how I ended up with early-onset Alzheimer’s, I would go with this: Being on the small size, even in high school, I compensated with over-the-top aggressiveness. I knew how to bring bigger players down by chopping them down at the knees. And I sometimes “saw stars” when I hit heads with another player, producing a sparkler effect at the margins of my vision. Decades later, soon after I was diagnosed with Alzheimer’s, I was contacted by my former football teammate Steve DeWitt, who was one year ahead of me in high school. Like me, Steve had no known family history of Alzheimer’s. At the time, it seemed obvious that my diagnosis was the result of high school football. Roughly 40 years after we’d had any contact between the two of us, we were each diagnosed, a single year apart. The gestation periods of the disease were virtually identical, even accounting for Steve being marginally older.But my wife, Paula, offered another suggestion. She suggested, sometimes in the realm of Alzheimer’s, things just happen, with no obvious cause of the disease. That could be the case. Still, if I were betting, I’d bet on head trauma, in the form of subconcussions. When Steve and I were playing football in the 1970s, no one had heard of this phenomenon. I expect to learn more about subconcussions in the years ahead. But for now I have to resign myself to the fact that there is no real way to pin down the cause of my dementia with certainty. Maybe that is for the better. My focus, after all, remains on doing whatever I can do to hinder my disease’s progress, through daily exercise, good nutrition, good sleep habits, and staying engaged mentally and socially. For now, short of a medical breakthrough, this is all we can do.